<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>用css3写一个环形进度条</title>
  <style>
    .circleProgress_wrapper {
        width: 200px;
        height: 200px;
        margin: 50px auto;
        position: relative;
        border:1px solid #ddd;
    }

    .left, .right {
        width: 100px;
        height: 200px;
        position: absolute;
        top: 0;
        overflow: hidden;
    }
    .left{
        left: 0;
    }
    .right{
        right: 0;
    }
    .circleProgress {
        position: absolute;
        margin: 0;
        width: 160px;
        height: 160px;
        border-radius: 50%;
        transform: rotate(135deg);
        border: 20px solid transparent;

    }
    .left .circleProgress {
        left: 0;
        border-top-color: green;
        border-left-color: green;
        animation: leftCircleProgress 5s linear infinite;
    }
    .right .circleProgress {
        right: 0;
        border-bottom-color: green;
        border-right-color: green;
        animation: rightCircleProgress 5s linear infinite;
    }
    @keyframes leftCircleProgress {
        0%,
        50% {
            transform: rotate(135deg);
        }
        100% {
            transform: rotate(315deg);
        }
    }
    @keyframes rightCircleProgress {
        0% {
            transform: rotate(135deg);
        }
        50%,
        100% {
            transform: rotate(315deg);
        }
    }
  </style>
</head>
<body>
<div class="circleProgress_wrapper">
  <div class="left">
    <div class="circleProgress"></div>
  </div>
  <div class="right">
    <div class="circleProgress"></div>
  </div>
</div>
</body>
</html>
